• Design & Manufacturing
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• 제15권1호
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• pp.1-7
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• 2021

The position of the gate is one of the important factors for optimal injection molding. This is because inappropriate gate positions cannot fill the cavity uniformly, which can lead to defects such as contraction. In this study, CAE was performed on hot runner injection molding of the washing machine base and plasticity was compared by changing gate position from existing gate position. A total of two alternatives have been applied to compare the plasticity of the washing machine base according to its optimal gate position. The gate position of the improved molds and the gate position of the current mold is analyzed by injection molding analysis. The results of the fill time, the pressure at V/P switchover, clamping force, and deflection were compared. In washing machine base injection molding, the deflection was reduced by about 3.76% in the improved mold 2. In improved mold 1, the fill time during injection molding was reduced by 3.32% to enable uniform charging, and the clamping force was reduced by 31.24%. We have confirmed that the position of the gate can change the charging pressure and the clamping force and affect the quality and cost savings of the molded product.

• International Journal of Costume and Fashion
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• 제6권1호
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• pp.56-70
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• 2006

The purpose of this study was to develop the high-value-added fashion cultural products with Korean image for the enhancement of global competitiveness. For this purpose, theoretical examination of the unique beauty of Korea and Korean image was first performed. Especially, characteristics of Korean traditional botanic patterns were investigated with LOHAS(Lifestyles of Health and Sustainability) philosophy which is the focus of the current design trend. Along with the above, the environmentally-friendly digital textile printing technology and Korean traditional botanic patterns were used to produce creative and globally-competitive fashion cultural products. Finally, a series of fashion cultural products were developed such as table runner, table mat and bedclothes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.628-632
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• 2002

Low voltage circuit breakers which interrupt rapidly and raise the reliability of power supply are widly used in power distribution systems. In the paper, it was investigated how much Interrupting capability was improved by correcting the shape of the contact system in molded case circuit breaker(below MCCB), especially arc runner. Prior to the interrupting testing, it was necessary for the optimum design to analyze electromagnetic forces on the contact system, generated by current and flux density. This paper presents both our compuational analysis and test results on contact system in MCCB

• 대한인간공학회지
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• 제20권1호
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• pp.63-72
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• 2001

Rearfoot control can be defined as the relative ability of a shoe to limit the amount of subtalar joint pronation immediately following footstrike. A normal amount of pronation provides a means of decreasing peak forces experienced by the leg, but excessive pronation of the foot can be arised its injures. The purpose of this study is to compare amount of pronation according to a difference between medial and later hardness of shoe midsole for better design of running shops. The experiment is examined for 7 running shoes. 8 males. to measure the Achilles tendon angle and rearfoot angle using high speed camera. The results is conducted that the changes of Achilles tendon angle significantly differ at each test shoe with increased running speed. And, a difference between medial and lateral hardness of midsole affects rearfoot motion of runner. The displacements of maximal Achilles tendon angle described a amount of pronation motion is decreased when medial hardness of midsole is large more than lateral.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 1부
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• pp.301-304
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• 2010

본 논문에서는 다수 캐비티 금형의 러너 내 불균일한 전단분포로 인해 발생되는 충전불균형에 따른 치수정밀도, 기계적 강도 등 물성의 차이가 발생되는 문제점을 해소하기 위해서 수지가 처음 분기되는 2차 러너의 구조에 변화를 주어 다수 캐비티 사출성형에서 충전균형을 위한 러너시스템을 제시하였다. 이 러너시스템은 전단률차이에 의한 즉, 온도가 불균일한 수지의 흐름을 혼합함으로써 수지의 흐름을 균일하게 하여 충전균형을 이루도록 하였다. PP수지를 대상으로 각 캐비티 간 균형충전에 대해 이 러너시스템이 효과가 있는지 검증하기 위해 CAE프로그램(Moldflow)을 이용한 유동해석을 통해 그 효과를 나타내 보았다.

• 한국정밀공학회지
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• 제12권3호
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• pp.110-118
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• 1995

The filling phase analysis of the injection molding process for thermoplastics was applied to predict pressure, themperature and shear stress in the test mold, and the results were compared with the experiment using 30% glass fiber added ABS resin. The finite difference method was used in the analysis considering the effects of heat transfer between molten polymer and mold wall, and also frictional heating by shear flow. The analysis results were considered as a method to improve the quality and the productivity of injection molding process. Using the analysis results, the molding factors such as mold-ability of polymers, performance of injection molding machine, positioning of gate and dimendsioning of runner in the injection molding process can be estimated at the design stage of mold for good quality and productivity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.250-254
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• 1998

Pump-storage power plants, which pumps water from the lower reservoir to the upper reservoir using the extra electronic power at night and generates the electronic power in the daytime, are more increasing. Currently it has a tendency to be high-head large-capacity machines. So in the processing of design, we need to know the vibration characteristics of pump-turbine shaft system sufficiently. In this paper, we developed the computer programs for analyzing pump-turbine shaft system considering magnetic force of generator, hydraulic force at runner, dynamic characteristics of guide bearings and the effect of add mass of water. And the superiority of this program was verified by applying it to the real model and calculating high quality critical speed, natural mode and unbalance response.

• Design & Manufacturing
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• 제8권2호
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• pp.50-55
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• 2014

Recently, semi-stack mold have been developed for satisfying the various elements required in the mold industry. The mold is possible using with general-purpose injection molding machine by weight reduction through the improvement of the mold structure. In order to do that, tension core, spiral cooling system and half runner system were applied. It is effective for increased productivity and decreased of loss to the materials. However, the mold is required the filling balance in order to improve the quality and efficiency. Thus this study performed that optimum design and analysis of semi-stack mold for filling balance.

• International Journal of Fluid Machinery and Systems
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• 제7권4호
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• pp.151-159
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• 2014

Low head hydropower is one of realistic renewable energies. The Darrieus-type hydro turbine with an inlet nozzle is available for such low head conditions because of its simple structure with easy maintenance. Experimental and numerical studies are carried out in order to examine the effects of gap distances between the runner pitch circle and two edges of inlet nozzle on turbine performances. By selecting narrower gaps of left and right edges, the performance could be improved. From the results of two dimensional numerical simulations, the relation between the performance and flow behaviors around the Darrieus blade are discussed to obtain the guideline of appropriate inlet nozzle design.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.92-96
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• 1997

Recently, the life cycle of products is rapidly shortened and then the disposal of the used mold applied in development of the product is a difficult thing. In this study, we proposed the feasibility of new 3plate type mold base for recycling by analyzing of the existing standard mold base. And in order to apply new 3plate mold base in mold design and making, we constructed the specifications for parts such as runner stripper plate, cavity plate, core plate and slide core unit. Also, we confirmed the possibility of recycling mold base by testing a used 3plate mold for a Audio front pannel.